After spending years searching for a planet with life,
scientists may have found one. In September 2010, a team of US scientists
discovered an Earth-sized planet called Gliese 581g. It has a surface
temperature neither too hot nor too cold for liquid（液態(tài)）water. Scientists think there is a chance that the
planet could have life.
The planet Gliese 581g goes around a star called
Gliese 581, which is about 20 light-years from Earth. That is about 194
trillion（萬億）kilometres －500
million times farther away from us than the moon.
A spacecraft traveling at a one-tenth of the speed of
light would reach Gliese 581g within about 220 years. A human can’t live that
long, but robotic explorers could make the job easier. However, our fastest
spacecraft don’t come anywhere near that one-tenth light-speed mark.
At present, scientists don’t know what the surface
might be like on Gliese 581g. What they know is that the planet is at the right
distance from its star to have liquid water. It’s also at the right distance to
have an atmosphere that could protect the water if it is on the surface.
Although spacecraft won’t be getting there anytime
soon, one way to look for life on Gliese 581g is to turn our radio telescopes（望遠(yuǎn)鏡）towards the planet and search for radiation（放射）. By studying the radiation, scientists would find out
about the chemicals（化學(xué)物質(zhì)）around the planet and discover if Gliese
581g has an atmosphere. If it has one, studying the atmosphere would give us a
good idea whether the planet has life or not. But it’ll probably be many years
before we can do this properly.
People have been arguing about whether there is alien
life on Gliese 581g. Any discussion about alien life is just guessing at this
point, according to its discoverers.
1.What did scientists find in September 2010?
A．A planet with
water. B．A planet
similar to the earth.
C．A planet
without life. D．A planet near
the earth.
2.According to the article, Gliese 581g ________.
A．is at the
right distance from its star B．moves around
the earth
C．is as far
away from us as the moon D．can be
reached in about 220 years
3.Paragraph 5 is mainly about ______.
A．the
possibility of living on Gliese 581g
B．the kinds of
chemicals around Gliese 581g
C．the way of
looking for life on Gliese 581g
D．the aim of
studying the radiation on Gliese 581g
4.Which of the following is the best title for the
passage above?
A．Gliese 581g,
a Likely Living Planet B．Gliese 581, a
Likely Living Planet
C．Gliese 581g
and Its Star D．Gliese 581g
and Radiation
